<!DOCTYPE html>
<style>
.flex-item {
    width: 50px;
    height: 50px;
}
.positioned {
    position: absolute; 
    left: 25px; 
    height: 25px;
    width: 50px; 
}
</style>
<div>This tests that z-index on non-positioned flex-items works. The green boxes should be above the orange boxes, which should be above the purple boxes, which are above the salmon boxes.<div>
<div style="position:relative">
    <div style="display:-webkit-flex;">
        <div class="flex-item" style="z-index: 1; background-color: salmon;"></div>
        <div class="flex-item" style="z-index: 100; background-color: orange;"></div>
    </div>
    <div class="positioned" style="top: 0; z-index: 150; background-color: green"></div>
    <div class="positioned" style="top: 25px; z-index: 50; background-color: purple"></div>
</div>
<div style="position:relative">
    <div style="display:-webkit-flex;">
        <img class="flex-item" style="z-index: 1; background-color: salmon;"></img>
        <img class="flex-item" style="z-index: 100; background-color: orange;"></img>
    </div>
    <img class="positioned" style="top: 0; z-index: 150; background-color: green"></img>
    <img class="positioned" style="top: 25px; z-index: 50; background-color: purple"></img>
</div>
